A suggestion for an additional way to describe a cfdg grammar about context-free HOT 3 OPEN

The single letter abbreviations already have long variants, except for x, y, and z. r and rotate are interchangeable, same for s and size, f and flip, trans and transform, h and hue, sat and saturation, b and brightness, a and alpha. skew has always just been skew, same with time and timescale.

We have already done a compatibility-breaking syntax change going from cfdg 2.x to cfdg 3.x. The code you are working with is in the old syntax, you can translate it here. I don't want to do another major syntax change unless it brings compelling new features.

On a side note, your code does randomness in the cfdg 2 manner, where random rule selection is the only way to make a shape do different things. With cfdg 3 you can have random actions inside a rule. Your grass code can be reduced to 5 rules:

startshape field

tile {s 150 }
background { hue 83.1 sat 0.4664 b -0.1255}

rule field
{
  grass{hue 97.6 sat 0.7282 b 0.7647}
}

# Add a chance to add a seedling. 
rule grass 5
{
  seedling{}
  grass{b -0.1…0.2 hue -0.1…0.1 sat -0.01…0.01
        r -5…5 x -10…10 y -10…10}
}

rule grass 0.1
{
  grass{r 0…360}
}

rule grass 0.01
{
  // end
}

rule seedling
{
  SQUARE{}
  seedling{y 1 r -2…2 s 0.991}
}

from context-free.

It is undesirable to elliminate startshape keyword, because it's a good way to switch between different branches during debugging. In the node based systems like Fusion, Nuke or Touchdesigner you can change the current node you want to output to the screen, just think of it in similar way.

from context-free.

I would never get rid of startshape. But I should make it optional. If there is no startshape then the first shape in the file is the startshape. I would rather do this than pick a default startshape name like main or scene because many non-english speakers use Context Free.

I think that adding a Pythonic syntax is a non-starter. But I would be interested in a ContextFree module for Python. I only know a little about Python. But it seems to me that function decorators could be used to allow shape rules to be expressed as Python code. The AGG rendering engine could be bound to Python as a C++ library. It would be a fun project for someone who knows a lot of Python. I would be glad to help if someone wanted to do this.

from context-free.